Telephone-exchange system.



E. E. HINRICHSEN.

TELEPHONE EXCHANGE SYSTEM.

APPLlCATlON FILED FEB. 20.1917- Patented July 9, 1918.

IIH"

, UNITED STATES PATENT OFFICE.

EDWARD n. HINRIGHSEN, or NEW YORK,

N. Y., ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y.', A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

. Application filed February 20, 1917. Serial N 0. 149,745.

To all whom/it may concern Be it known that I, EDWARD E. HINRIGH- SEN, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and use-fullmprovements in Telephone-Exchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone exchange systems ofthe central office type, its object being the production of improved sig naling means in such systems; 7

In accordance with a feature of this in vention, a sleeve relay associated with one end of the link circuit cooperates with the supervisory'relay and a locking relay to-control the intermittent operation of the signaling device.

In accordance with another feature of this invention, a differentially wound listening relay, controlling the connection of the operators telephoneset to the cord circuit, has its operating winding in circuit with the supervisory signaling device, and the resistance which forms a shunt for the supervisory signaling device is wound on the diflerential relay in the form of a compensating winding. 1

This invention is illustrated in the accompanying drawings in which all apparatus is shown in its normal and unactuated condition. 7 V

There is shown in the drawing a telephone exchange system containing one embodiment of this invention and comprising subscribers lines A and B, terminating at a central oflice, and a cord circuit C thereat for connecting the subscribers? lines. -f It will be understood that a plurality of lines, similar to A and B, terminate at the central office, but, for the sake of simplicity, only the two lines are shown. It is believed that the invention will be fully understood. from a description of the operation ofthe system shown in the drawing, and it will be so described. I r

Assuming that subscriber A desires to be connected with subscriber B,- A will signal the central oflice in .the usual manner, whereupon the operator inserts the answering plug of the cord circuit C'into the ack associated with line. A. Cut-off relay 5, listening relay 6 and supervisory relay thereupon operate.

' Specification of Letters Patent. v

. ing thereof.

Patented July 9, 1913.

through'contact .11 of relay 10, contact of supervisory relay 7 contact 12 of relay 10,

upper winding thereof, windings 15 and 9 of relay '6, and sleeve contacts of the answering plug and jack, and the winding of relay 5 to ground. The upper winding of relay 10 and winding 15 of relay 6 are of low resistance and form a shunt for answering supervisory lamp 8, thereby preventing the light- Upon the shunt circuit for lamp 8 being established, there is an in creased flow of current through winding 9 of relay 6, and the connections of winding 15 of relay 6 are suchthat this winding servesto compensate for this increased flow of current through winding 9, with the re vsult that the net energization of the-relay 6 is not increased after the establishment of the shunt circuit forlamp 8.

-Upon being advised that subscriber A desires to be connected to the line of subscriber B, the operator inserts the calling plug of the cord circuit G into the jack of line B, whereupon the calling sleeve relay 20 and cut-off relay 21 operate, and calling supervisory lamp 23 is lighted. Upon the operation of calling sleeve relay 20, a circuit is completed through winding 22 of relay 6. The direction of flow of current through windings 9 and 22 of relay 6 isopposite, so that, upon the establishment of the circuit through winding 22, relay 6 releases, disconnectin the o )erators tele )hone set from the cord circuit, and opening the operating circuit through the lower winding of relay 10. The operator may signal subscriber B in any desired manner. Subscriber B, in respondlng, removes the recelver from the switchhook and causes the operation of calling supervisory relay 24, which closes a shunt circuit containing a resistance 25 about the calling supervisory lamp 23, which is thereupon efi'aced.

The subscribers, upon finishing conversae t1on, restore their receivers to the switchhooks, vvhereupon superv sory relays 7 and calling supervisory lamp 23"to' light 'to furnish a disconnect signal- The release of the answering supervisory relay 7 opens the locking, circuit throughrelay 10, whereupon this" relay releases, "connecting interrupter 26 to the armature of answer-ing supervisory relay 7. The release of relay 7 also removes 1 the shunt from about supervisory lamp 8,

"whereupon this lamp lights to furnish a dis connect signal; 'vvithdraw'theplugs from thejacks, where- The' operator" may then uponfall apparatus returns to normal.

" Suppose, however, that before the plugs are'vvithdrawn from the'j acks, subscriber A should vdesi're to make a recall, then theremoval of the receiver from the switchhook by subscriberAgcauses the intermittent operation of the supervisory lamp- 8 to furnish a recall signal to" the operator. This is' accomplished in the following manner: The removal of the receiver from the 'switchhook "by subscriber *A' causes-the operation of supervisoryrelay 7 which connects the interrupter 26 incircuit Withresistance 27, the'compensating winding 15 and operating ivinding"9* "of relay' 6, sleeve contacts of answering plug and jack, and the Winding of cut-ofi'" relay to ground. Theresistance 27 has thesame value as the upper inding ofrelay' 10, and with compensating Winding 15 forms a shunt for answering supervisory lamp 8. It Will-be seen, therefore, that 111 v.the operation of'interrupterv 26, this shunt,

comprising the resistance 27 and compensating "Winding 15, is intermittently placed about the lamp 8,'Whereby this lamp is intermittently; operated to furnish a recall signaltotheoperator. The operator, upon observing'lt'heintermittent operation of the answering supervisoryglamp 8, Wlll actuate 'key 28,'whereupon the neutralizin winding '22 of relay 6 will beshortcircuite by direct causin battery through-normal contact of calling 's'upervi'soryrelay' 24. Relay 6 thereupon attracts its armature's, connectingthe operatorstelephoneset-to the cord circuit, and the operation of relay-'10, Which ,immedlately establishes a-locking circuit for y from the'jack line B, restores key 28 to'npritself as hereinbefore traced. 'The'operator, upon being advised of the number ofthe sub scriber desired, Withdraws the calling plug male posit on, and completes the connection "With the desired subscriber in the manner 'hereinbefore described.

What is claimed is:

l. A telephone exchange system comprising'telephone lines, a link circuit for interconnecting the; lines, a supervisory relay and a second relay operating upon the connection of the link circuit w'ith acalling line,

relay.

aQthird E-reIay actuated upon the operati n of the second relay, a locking circuit for the third relay including a Winding of th sec- 24'release. ,T he releasefof relay 24 causes ond relay established upon the; operation of the second relay and the" supervisory relay,

a signaling device, and a source of intermittent current brought'into circuit with the ,s1gnal1 ng dev1ce upon the subsequent deenergization of the third'relay and the enerigization of ftheasupervisory relay.

2. A telephone exchange system compris- 1ng telephone llnes, a link c1rcu1t I EOI-I1Ilt61- connecting the l 1n'es,asupervisoryrelay and a second relay energizedlupon the connection of the link circuit with a calling'line, a third relay actuated upon the energization'of the of intermittent current brought into circuit with the 1 signaling i device by the subsequent 'deenergization of the third relay-followed by the energization of the supervisory. :relay:

telephoneexchange system compris- 111g telephone lines, a link c rcuit fo-rinten.

'c'onnectingthe lines,a supervisoryrelay and "alistenin'g relay operating upon the r011- nect-ion of the link circuit with a calling line, an operators telephone set connected with the operation of the listening relay, a locking circuit for the third relay including a Winding of the listening relay established the link circuit 'uponthe operation of the listening relay, a-gthi-rdi relay actuated upon upon the operation of thethird relay and -f:

the supervisory relay, a-signaling device,

e and a source of intermittent current brought into circuit With the signaling deviceupon the subsequent deenergization of thethi-rd relay and the operation of the supervisory- 4. A telephone exchange system comprising telephone lines, a link circuit for interconnecting the lines, a supervisory relay" and a listening relay operated .upon" the con-- *nectlon of the link circuit With a calling line,

an operators telephone set connected with c {the link circuit upon the operation of the :listenmg relay,;a third relay actuated upon the operation ofthe listening relay,- a lock-'- ing circuit for the third relay established uponlthe operation thereof for rendering this relay independent of the listening relay,

a signaling device, and a source of intermittent current brought into circuit with the slgnaling' device' 'by" the subsequent 'deenergization of the third relay followed by the energ zation of the supervisory relay.

5. A telephone exchange system compristrolling the connection of the operators telephone set to the link circuit,"a supering telephone lines, a link circuit, an operators telephone set, a listemng relay c011 cuit therefor established upon the energization of the listening relay, a signaling device, interrupter mechanism, and a circuit including the signaling device, a winding of the listening relay and the interrupter mechanism established by the subsequent deenergization of the third relay followed by the energization of the supervisory relay.

6. A telephone exchange system comprising telephone lines, a link circuit, an operators telephone set, a listening relay controlling the connection of the operators telephone set to the link circuit, a supervisory relay, a third relay actuated upon the energization of the listening relay, a locking circuit therefor including a winding of the listening relay established upon the operation of the third relay and the supervisory relay, a signaling device and interrupter mechanism, and a circuit therefor open at two points, the circuit being closed at one point by the subsequent deenergization of the third relay upon the release of the supervisory relay, and atthe other point by the subsequent energization of the supervisory relay to cause the intermittent operation of the signaling device.

7. A telephone exchange system comprising telephone lines, a link circuit for interconnecting the lines, a listening relay having an operating, a compensating and a neutralizing winding, a signaling device, a circuit including the operating Winding of the listening relay and the signaling device established upon connection of one end of the link circuit with a line, an operators telephone set controlled by the listening relay, a supervisory relay, a shunt circuit comprising the compensating winding of the listening relay connected about the signaling device upon the energization of the supervisory relay, and a circuit including the neutralizing winding of the listening relay completed upon the connection of the other end of the link circuit with another line.

In Witness whereof, I hereunto subscribe my 7name this 19th day of February, A. D. 191

EDWARD E. HINRICHSEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

